Outboard motor construction



Feb. 18, 1941. M. A. BLU 'ET AL CUTE OAR? MOTOR CONSTRUCTION Filed Dec. 10, 1936 4 Sheets-Sheet, 1

jizziezzzbrs Feb.'18; 1941. M. A. B LU HAL 2,232,160

OUTBOARD moron consmmnon Filed Dec. 10, 1936 ,4 sinus-sheet 2 fizqeiztvili Marshall .flfilu Frank M. Morgan) Lawrencelfflempagy 3y M 69.4,, a? W afiiomggfi Feb. 18, 1941. M AL I 2,232,160

OUTBOARD MOTOR CONSTRUCTION Filed Dec. 10, 1936 Y 4 Shts-Sheetfi iiiiii fizue/ztora Marshall JZBLLL "Frank MQ/Voryar;

3y Zawrezzce Eflempqgy v *a itomayi Feb. 18, 1941. M. A. BLU ETAL 1 2,232,160

OUTBOARD MOTOR CONSTRUCTION Filed Dec V10, 1936 4 Sheets-Sheet 4 I LawrenceEDempsQy firm/c M Morgan Patented Feb. 18, 1941 UNITED srArEs PATENT OFFICE 2.232.160 OUTBOARD Moron CONSTRUCTION Marshall A. Bin, Chicago, Frank M. Morgan, Glen Ellyn. and Lawrencev E. Dempsey, Oak Park, Ill., assignors to- Sears Roebuck and 00., Chicago, Ill., a corporation of New York The invention relates to improvements in outboard motor construction.

' One object of the invention is to provide an improved outboard motor structure in which the power unit or engine, and its accessories are arranged in a. compact assembly with all manual controls grouped at a central control point for convenient access, and in which the engine and associated parts are enclosed to provide an attractive, streamlined appearance.

7 Another object is to provide an improved fuel tank support and engine enclosing structure for outboard motors in which the parts are assembled in a compact, rigidunit capable of being quickly is and easily assembled with the other elements of the motor and adapted to be readily detached therefrom for repair "or replacement.

Another object is to provide an improved fue tank system for outboard motors.

Still anotherobject is to provide improved means for enclosing the control mechanism of outboard motors whereby the mechanism is effectively protected and the general appearance of the motor is improved by reason of the control elements being concealed.

A further object is to provide improved means for controlling-the' ignition system of an outboard motor.

It is" also an object of the invention to improve and simplify the construction and arrangement of the individual parts'of the motor structure with a view of facilitating manufacture and assembly of the same, and providing an outboard motor which is eflicient and reliable in operation,

which is well balanced and attractive in appearance, and which can be manufactured at a relatively low cost.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment disclosed in the accompanying drawings. It will be understood, however, that various changes in form, construction and arrangement of the parts may be made by those skilled in the art without departing from the spirit and scope of the in- Fig. 3 is 'a. sectional view'takenialong the line 33 of Fig. 1. Y

Fig. 4 is an elevational view of the upper part struction.

away to show the arrangement of the fuel supply and ignition control means.

Fig. 5 is a front elevation of the upper part of the motor. 5

Fig. 6 is a rear elevation of the upper 'part of the motor.

Fig. 7 is a plan view of the motor with a part of the shielding structure broken away to show the fuel tank support. 10

Fig. 8 is a sectional view taken along the line 8-8 of Fig. 1.

Fig. 9 is a sectional view taken along the line 9-9 of Fig. 4. Referring to Fig. 1 of the drawings, the out- 1 board motor selected to illustrate the invention comprises a water cooled, two-cycle internal combustion engine having a crank case It) and a ,cylinder H mounted in a horizontal position-on the upper end of a vertical; drive shaft housing I2. 20

The crank case in is in the form of a unitary casting and is provided with upper and lower bearings l3 and It for supporting a crank shaft II in a generally vertical position. A piston i6 operating in the cylinder-Ii is arranged to drive 25 the crank shaft through the medium of a connecting rod i1.

Mounted on the projecting upper end of the crank shaft I5 is a suitable flywheel Hi to which is bolted a starting plate IQ of conventional con- 30 A vertical drive shaft 20 is keyed to the lower end of the crank shaft andextends through the housing l2 to a suitable propeller gear housing 2| carried on the lower end of the drive shafthousing. The gear housing 2ien- 35 closes conventional gear mechanism for drivingly connecting the shaft 20 with a propeller 22' and a water pump 23. The gear housing also supports a suitable anti-cavitation plate 24.

As shown in'Flg. 1, the drive shaft housing I2 40 comprises an upper section 25 in the form of a. hollow casting and a streamlined tubular lower section 26 (Figs. 2 and 3) connecting 'the section 25 with the propeller gear housing 2 I. The upper section 254s adapted to be bolted or otherwise 45 rigidly secured to' the cylinder and crank case assembly and is arranged to communicate with the interior of the cylinder ll through an ex-' haust port 21 in the cylinder casting as shown in Figs. 1 and 8. The exhaust gases from the cylinder are thus conveyed through the shaft housing and discharged through an opening 28 in the tubular section 26, the opening preferably being at a point below the water line to .muiiie the exhaust noise; The casingsection 25 is also as on the housing section 25 by means of a sleeve member 34 engaging in a channel-shaped bearing 35 formed on the housing section. An abutment block 36 on the bracket engages an annular bearing surface 36 formed on the lower portion of the housing section to hold the motor assembly rigid with the bracket.

Fuel and air'mixture for operating the internal combustion engine is supplied to the cylinder H by'a carburetor or mixing valve 40 (Figs. 1 and 4) mounted on the forward end of the crank case l0 and communicating therewith through a port 4|. The mixing valve may be of any preferred construction and, as herein shown, comprises the usual lift member 42 normally closing the air and fuel ports and adapted'to be raised by suction created by the piston on its compression stroke to admit fuel and air to the crank case. The fuel and air mixture thus drawn into the crank case in one stroke of the piston is compressed in the next working stroke thereof and the compressed mixture is discharged into the cylinder through an intake port 43. which is uncovered by the piston as it approaches the end of its working stroke. The lifting member 42may be raised manually by means of the stem 42 to facilitate starting of the engine.

A needle valve 44 of any suitable construction controls the flow of the fuel to the mixing valve.

Adjustment of the needle valve is effected by means of a rotatable member having a knob 45 arranged in a conveniently accessible position at the forward end of the motor structure. As shown in Fig. 5, the knob may-be formed with a peripheral flange 46 graduated to provide a visual indication of the valve setting. 7

Fuel is fed to the mixing valve 44 by gravity from suitable tanks 41 and 48 mounted on the upper part of the motor structure and preferably located on opposite sides of the engine to provide a well balanced assembly as shown in Fig. 4.

While tanks of any suitable shape and construction may. be used, it is preferred to employ a streamlined tank of generally ellipsoidal or tear drop form, having a relatively blunt forward end and an elongated tapering rear end as shown in Fig. '7. Such tanks provide ample fuel storage capacity in a comparatively small space and materially improve the appearanceof the motor.

The tanks 41 and 48 are connected by a feed line 49 in which is interposed a T-fitting 50 connecting the line with the needle valve 40. Thus the feed line in addition to delivering fuel from the tanks to the engine serves to equalize the fuel between the two tanks. I With this construction only one of the tanks need be provided with an opening for'filling purposes while the other tank requires only a small opening for admitting air to and from the tank to equalize the pressure therein. As herein shown the filling opening is provided in the tank 41, the body of the tank being struck outwardly to form an upwardly pro- .iecting flange 5| for this purpose. A corresponding flange 52 on the tank 48 provides an air open ing for .this tank. The openings may be closed by the usual vented screw caps 53 and 54, respectively.

The fuel tanks and their supporting structure are preferably constructed and arranged so that they may be assembled with or detached from the. motor structure as a unit.. To this end, each of the tanks is provided with an outwardly projecting flange 55 brazed or otherwise rigidly secured to the inner side wall, as shown in Figs. 4 and 7. These flanges are secured by suitable means such as bolts 56 to opposite side edges of a rectangular supporting plate 51 which, in turn, is adapted to be removably secured to the cylinder and crank case castings as by bolts 58.

As shown in Fig.7, the supporting plate 51 is formed with a generally rectangular aperture 59 for receiving the upper part of the crank case I0 and the crank shaft bearing l3. The-plate is of suflicient width to project laterally slightly beyond the rim of the flywheel I 8 so that the fuel tanks 41 and 48 are held closely adjacent thereto and extend longitudinally of the cylinder and crank case assembly. I I A member 68 secured between the fuel tanks 41 and 48 provides additional rigidity to the tank assembly and serves to enclose the upper part of the engine and its accessories. The member 68 may be of any suitable shape and construction and, as herein shown, is formed with a slight convex curvature as viewed in longitudinal section. The rearward end of the member-may be' rolled downwardly and inwardly as shown in Fig. 1 to avoid leaving a sharp exposed edge and to secure lateral rigidity. The member 68 terminates at its forward end in a generally rounded downwardly projecting flange portion 6| to which is secured a front cover plate 62. The cover plate 62 extends downwardly andthen rearwardly tothe underside of the crank case I to which it is removably secured by bolts 62* thus comprising, with the member 68, a casing structure for enclosing engine accessories and control devices as will appear presently. A beaded aperture 63 in the member 60 permits the flywheel II to P oject therethrough. I

To avoid any possibility of injury to the fuel tanks or engine cylinder when the motor is placed in a reclining position, legs 64 are bolted to cpposite side edges of the supporting plate 51 and arranged to extend rearwardly beyond the'end' on the floor or other surface and, with the supporting plate, carry the weight of the motor. A transverse member 65 brazed or otherwise rigidly secured to the fuel tanks 41 and 48 at points closely adjacent the rear edge of the supporting plate stin'ens the entire tank structure and prevents the supporting plate from bending under the weight of the motor. I In accordance with the usual practice, the engine of the outboard motor is provided with electrical means in the formlof a spark plug 68 for igniting the fuel and air mixture in the cylinder ll. While a battery and spark coil may be employed for supplying high tension current to the park plug, the preferred construction contemplates the use of a flywheel type magneto of well w to vary the timing of the spark. When magneto ward or switch opening position. with the .rod

ignition is employed, the adjustment is effected,

by varying the position of the armature coils i8 relative to the axis of the flywheel. To this end, the coils are mounted on the adjusting member which is in the form of a generallycircular plate 69 having a centrally disposed bearing III for supporting the member loosely on the hub of the crank shaft bearing i3'concentric with the flywheel I 8. A flexible conductor H connects the armature coils with the spark plug 66:

Suitable manually operable control meansconve'niently accessible at the front of the motor structure is provided for rotating the magneto adjusting member 69 to regulate the timing of the engine. In its preferred form, the control means comprises a tubular control member 12 rotatably supported on a substantially horizontal axis perpendicular to the axis of the crank shaft I5 and drivingly connected with the adjusting member. Support for the member is provided by a rear bearing I3 carried on a bracket 13 (Fig. 9) on the forward end of the crank case casting l0 and a front bearing formed by a downwardly bent section til -at the forward end of the fuel tank supporting plate 51.

The driving connection between the contro member 12 and the adjusting member 69 preferably comprises a pinion I4 rigidly secured to the control member as by a set screw and adapted to mesh with a gear sector 16 carried by the adjusting member. Thus, by rotating the control member 12, the position of the adjusting member 69 and armature coils 68 mounted thereon may be varied as required to obtain efficient operation of the engine. Rearward longi-v from working loose due to vibration of the engine.

The control member 12 is arranged to project forwardly beyond the casing structure 62 above and closely adjacent the valve adjusting knob 45. A lever or handle 80 fast on the projecting end of the member provides a convenient means As herein shown, the handle 80 is formed with a radially projecting tip 8| constituting a pointer for cooperating with a graduated scale 82 to give a .visual indication of the magneto setting. The

scale may be formed integral secured to the casing 62.

Means is also provided for short circuiting or grounding the magneto to interrupt. the supply with or suitably of high tension current to the spark plug it and.

thus stop the engine. As hereirr shown, this means comprises a suitable grounding switch having a stationary contact 83 electrically connected with the magneto armature coil and a movable contact 84 grounded on the frame of the motor.

. mounted on thecrank case Ill and insulated therefrom by a suitable electrical insulator 3!. The contact 84 is mounted on the inner end of. a cylindrical rod 8 slidably supported for endwise movement within the tubular control member 12. The rod to is formed with an enlarged end portion 81 and a compression spring I. interposed between this enlarged end portion and a shoulder formed on the interior wall of the control member, tends to maintain the rod, in a for- The contact 83 may befconveniently in this position, the end portion projects forwardly beyond the end of the control member and the handle and constitutes a stop button by which the rod may be shifted manuallyinto switch closing position to stop the motor.

It will be observed that the various control devices including the magneto adjusting lever or handle 80, the stop-button 81, the needle valve adjusting knob 45, and the mixing valve stem or choke member "*are all convenientlygrouped at the forward end'of the motor structure on a control panel provided by the cover plate 62. The controls are therefore readily accessible to the operator. Morover, the cover plate con- 'stitutes a casing structure which effectually cov- I assembly with the various elements effectively enclosed to present an attractive streamlined appearance. The fuel tanks, enclosing structure and their supporting means are assembled in a compact, rigid unit which can be quickly and easily assembled with themotor structure and can be readily detached therefrom for repair or replacement. The fuel storage system embodies a plurality of tanks interconnected for operation as a unit and arranged in a manner such 'as to improvethe general appearance of the motor. Emcient and practical control means is provided for adjusting the magneto to obtain proper timing of the motor under varying operating conditions. Moreover, control of the motor is material- -ly simplified by grouping allcontrols in closely adjacent relation on the forward end of the motor structure where they are conveniently accessible to, the operator.

I We claim as our invention:

1. An outboard motor structure comprising, in combination, an internal combustion engine, a unitary fuel tank structure including a pair of streamlined fuel tanks each having anoutwardly projecting longitudinal flange extendingfl'along one side thereof, a rectangular plate adapted to be removably secured at opposite sides to the flanges of the respective tanks to support the tanks in spaced relation, a tubular member extending between the tanks and rigidly secured thereto at opposite ends to provide additional rigidity for the structure, an engine enclosing member extending between said tanks and rigidly secured thereto at points spaced substantially above said flanges and said tubular members, and 1 on said engine, said supporting means including a rectangular supporting. plate removably secured to the top of said engine in a generally horizontal position and arranged to project on opposite sides of the engine, an outwardly projecting longitudinal flange on each of said tanks. and means for detachably securing the flanges of the respective tanks to the projecting portions of said member"to support the tanks on said M c s e,

3. An outboard motor structure comprising, in combination, an internal combustion engine, a pair of fuel tanks for supplying fuel to said engine, and means supporting said tanks on opposite sides of said motor, said supporting means including a rectangular plate extending across and removably secured to said engine, and means rigidly securing said tanks to opposite sides of said plate, p

4. An outboard motor structure comprising, in combination, an internalcombustion engine having horizontally disposed cylinder means mounted on the upper end of a vertical drive shaft housing, fuel tanks for supplying fuel to said engine, means supporting said tanks on said engine, and a pair of spaced legs mounted on said supporting 'means and extending rearwardly of said cylinder means for supporting the'weight of the engine and protecting said cylinder and said tanks when the motor structure is disposed in a horizontal position.

5. An outboard motor structure comprising, in combination, an internal combustion engine, a

pair of fuel tanks for supplying fuel to said engine, a rectangular plate detachably secured to the top of said engine in a generally horizontal position, the tanks being secured to opposite side edges of said plate, and an engine-housing member spaced above said plate and rigidly secured and said tanks being removable as a unit by detaching said plate from said engine.

6. An outboard motor structure comprising, in

combination, an internal combustion engine, and

a unitary fuel tank structure comprising a pair of elongated fuel tanks in laterally spaced relation, and. a pair of vertically spaced plates attached at their side edges to the respective tanks, the upper plate constituting a housing member 'to said tanks, said plate said -housing member and the lower plate being detachably secured to 

